The present invention relates to a technique for correcting a defect of a tip needle portion of a manipulator for handling a fine sample or a fine structure, which is set in a vacuum chamber of a focused ion beam (FIB) device, using the FIB.
As a method of creating a sample for a transmission electron microscope (TEM), a technique for subjecting a semiconductor wafer to lamination machining using a focused ion beam (FIB) device is known. In order to carry a fine section sample, which is obtained by cutting a sectional portion subjected to the lamination machining, onto a sample stand and hold the fine section sample on the sample stand stably, a micro-manipulator is used. JP-A-2001-141620 proposes a machining method of, as shown in FIGS. 7A to 7D, irradiating a focused ion beam on a wafer sample from a position above a sample surface to etch both sides of an observation section, scanning a sample, which is obtained by tilting the sample surface in a state in which a front hole and a rear hole are drilled and lamination progresses appropriately and subjecting the sample surface to lamination machining, using the focused ion beam to perform cutting for side portions of the sample surface (FIG. 7A), holding a section sample surely using a manipulator (only a glass probe, which is a tip portion of the manipulator, is shown in the figure) after lamination finish machining (FIG. 7B) and transferring and placing the section sample on a mesh (FIG. 7C), and creating a sample for TEM observation stably (FIG. 7D). In the handling for treating a fine piece such as this section sample in the vacuum chamber, a manipulator for enabling drive operation in a fine space and a sharpened needle for grasping the fine section sample are provided. This is a so-called micro-manipulator. Metal such as tungsten W or platinum Pt is used for the needle. However, if the needle is sharpened to about several μmφ, the needle is susceptible to an external shock and is bent at a tip portion thereof when the needle grasps and manipulates a sample. Since it is not easy to repair this needle to be straight, the needle is replaced eventually.
As a technique for forming a needle structure of a submicron order using the FIT device, it is publicly known to form a probe of an atomic force microscope (AFM). The probe of the atomic force microscope (AFM) is provided at a cantilever tip portion. Conventionally, as this probe, a cantilever including the probe at the tip portion is created using a micro-fabrication technique such as lithography and etching with silicon nitride or silicon as a base material, and a probe portion of the cantilever is oxidized and then sharpened by removing an oxide film with etching. However, the probe tip serving as a sensor portion may be required to be sharpened as a probe for the AFM. Therefore, a technique for forming a firm cylindrical chip of a conductive material such as tungsten or DLC (diamond-like carbon) with the CVD using the FIB in the cantilever tip portion is disclosed. FIG. 8 shows a photograph of the chip. The probe formed in this way is structurally thin and high in abrasive resistance and has necessary rigidity. The probe is attached to the cantilever tip and formed such that the chip is perpendicular to a sample surface. In addition, the material has electric conductivity, and the probe has stable resolution and high measurement reproducibility (see, for example, JP-A-2003-240700). In addition, K. L. Lee et al. proposes a deposition chip that is formed by irradiating an electron beam at a tip of a chip of a cantilever in a vacuum chamber of a scanning electron microscope (SEM) and depositing a carbon decomposition product using an electron beam on the irradiated portion (see FIG. 9: an image on the left indicates that a chip is formed at a tip of a probe portion at a cantilever tip and an image on the right is an enlarged image of the probe tip portion) (K. L. Lee et al.: “Submicron Si trench profiling with an electron-beam fabricated atomic force microscope tip” J. Vac. Sci. Technol. B, vol. 9, No. 6, Nov/Dec 3562-3568 (1991)).
In the needle defect correction in the conventional technique, first, work is suspended to release a vacuum state in a chamber, then, the chamber is opened to remove and repair a probe, and the probe is attached again or replaced. This work requires long time and high cost. Moreover, the work continued after the replacement has to be started all over again from creation of a vacuum state. A sample being created is often lost, which causes large temporal loss and work load for an operator.
In the chip forming method using the electron beam deposition, whereas a thin cylindrical chip can be formed, the chip is susceptible to shock and has insufficient strength as a chip for the AFM.
It is an object of the invention to propose a method of correcting a defect, which has occurred in a tip needle portion of a manipulator provided in an FIB device, without consuming time and labor. In addition, it is another object of the invention to propose a technique that, when abrasion or breakage of a probe of a probe microscope or bend or breakage of a micro-manipulator occurs, makes it possible to repair and restore the probe or the micro-manipulator in a vacuum chamber without removing and replacing the probe or the micro-manipulator.